Proactive prosociality in a cooperatively breeding corvid, the azure-winged magpie (Cyanopica cyana).

Lisa Horn,Clara Scheer,Thomas Bugnyar,Jorg J M Massen

doi:10.1098/rsbl.2016.0649

Abstract

One of the contemporary hypotheses concerning the evolution of human altruism is the cooperative breeding hypothesis (CBH) which has recently been tested in non-human primates. Using a similar paradigm, we investigated prosociality in a cooperatively breeding corvid, the azure-winged magpie. We found that the magpies delivered food to their group members at high rates, and unlike other corvids, they did so without any cues provided by others. In two control conditions, the magpies stopped participating over time, indicating that they learned to discriminate prosocial tests from controls. Azure-winged magpies are thus the first birds that experimentally show proactive prosociality. Our findings are in line with the CBH; however, additional corvid species need to be tested in this promising paradigm.

Highlights

The evolution of altruism remains a highly debated topic, because the first studies on prosociality in chimpanzees rendered negative results (e.g. [1]), and prosociality was subsequently considered a human hallmark
One of the hypotheses that tries to explain the evolutionary reasons for this mixed pattern is the cooperative breeding hypothesis (CBH), originally developed based on the relatively high prosocial tendencies of cooperatively breeding common marmosets [3]
The evenness of distribution assessed in phase II was high in both groups (NB: Pielou’s J0 1⁄4 0.74; B: J0 1⁄4 0.85; table 2)

Summary

Introduction

The evolution of altruism remains a highly debated topic, because the first studies on prosociality in chimpanzees rendered negative results (e.g. [1]), and prosociality was subsequently considered a human hallmark. The most convincing evidence for the CBH so far is a comparative study of 15 primate species that showed that species-specific prosocial tendencies in a group service paradigm were best explained by the degree of allomaternal care [4].

Results

Conclusion